Springtail (Collembola) assemblages along an elevational gradient in Australian subtropical rainforest

Springtails are one of the most abundant groups of arthropods inhabiting soil and litter substrates within rainforest ecosystems, making significant contributions to ecological processes such as decomposition. The aim of this study is to assess the potential sensitivity of springtail assemblages to climate change by presenting some of the first data on the elevation stratification of springtail assemblages in subtropical rainforest. A standardised sampling protocol was used to compare the assemblages of families and species of springtails living within leaf-litter at three elevations in continuous rainforest in south-east Queensland, Australia. Leaf-litter was collected and springtails extracted from four replicate plots at approximately 700, 900 and 1100m a.s.l. on two sampling occasions (January 2008 and December 2008). Environment variables (elevation of plots, tree species richness, composition and basal area, soil temperature and moisture and a range of physical and chemical properties of the soil) that may correlate with springtail distributions were incorporated into the analyses. Springtail assemblages showed clear elevation patterns, despite some differences between the two sampling occasions. Springtail assemblages characteristic of different elevations particularly when examined at a finer taxonomic resolution (species compared with family-level identification) were identified. Plot elevation (m a.s.l.) correlated most strongly with patterns in springtail species assemblages, but was also highly correlated with several other environmental factors. The results indicate that springtails, as a group, respond strongly to the physico-chemical and/or biological changes that occur with increasing elevation, even over a relatively small elevation range, demonstrating that they have potential as monitoring targets as forests experience climate change.